Ivc filter retrieval systems with interposed support members

ABSTRACT

Funnel-trap type delivery and/or retrieval devices for Inferior Vena Cava (IVC) filters or other medical implants are described in which the devices comprise two layers of braid with an axially support member. The support member may be interposed between braid layers or set inside the braid layers but interposed between heatset features. Delivery and/or retrieval devices, kits in which they are included, methods of use and methods of manufacture are all contemplated herein.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/965,500, filed Dec. 10, 2015, which claims the benefit of andpriority to U.S. Provisional Patent Application Ser. No. 62/091,433filed Dec. 12, 2014, both of which are incorporated by reference hereinin their entireties and for all purposes.

FIELD

The embodiments described herein relate to endovascular temporaryInferior Vena Cava (IVC) filter, other implant or other foreign bodyretrieval devices or system and methods.

BACKGROUND

Temporary IVC filters are placed much like permanent filters, but aredesigned so that they may be retrieved in a separate endovascularprocedure, generally from a femoral vein or internal jugular veinapproach. Most of the currently available temporary filters include ahook-like feature with which they can be captured and received within acatheter or sheath for removal by employing a gooseneck snare or amulti-loop snare.

While retrieval is a simple procedure in principle, difficulty is oftenencountered capturing a filter's hook with the snare loop(s). Suchdifficulty is compounded when the filter is tilted or off-kilter inplacement. Several filters are designed to avoid such orientation.However, the problem remains common because the device is not anchoredinto the IVC in a stable fashion. Constant blood flow in addition toblood clots can disorient the filter within the IVC making recapturedifficult.

Accordingly, there exists a need for a filter retrieval system withimproved ease of use and/or less susceptibility to problems of filterorientation.

SUMMARY

Embodiments hereof meet this need and others as applied to other medicaldevice applications. For IVC filters, the subject systems may be usedwith a wide variety of filter architectures—existing or otherwise.Accordingly, new filters may be designed for use with the subjectretrievers in which fewer design constraints and/or compromises may berequired of the filter design. Features of the subject system may beused in connection with existing and/or modified versions of the filtersdescribed in any of U.S. Pat. Nos. 3,952,747; 5601595; 6,443,972;7,338,512 and 7,625,390 (all of which patents are incorporated herein byreference in their entireties for any purpose), with commerciallyavailable devices including the OPTEASE, GÜNTHER TULIP, CELECT andOPTION or others.

In the subject embodiments, one or more members are interposed betweenbraid layers defining a funnel trap in the subject device. In oneembodiment, the support member may resemble a flower. The support membermay comprise a polymer, Nitinol (superelastic at body temperature orbelow) or other metal or alloy. Especially when the “flower” comprises athermoplastic material or Nitinol, the “petals” of the so-called flowermay be heatset flat at appropriate temperatures as understood by thosewith skill in the art. In another embodiment, the support members areindependent and stabilized between layers of braid as having a hook or“J” shape. These may be originally cut from flat stock or a tube ofpolymer or metallic material. Such member may be further stabilized bysuture loop(s) through or around each such member or body.Advantageously, any knot securing the suture can be positioned withinthe interior of the funnel trap section of the device. This can beaccomplished by tying the knot(s) on the outside and then pivoting thetrimmed structure through the braid from which the device isconstructed.

In the so-called flower embodiment, a single such member may be used. Itmay be advantageously cut with four strips, slats, leaflets orpetals—collectively, “support elements.” More cuts may be made (e.g.,with a blade or laser) to define a greater number of elements. However,since it is advantageous for these members to have a largewidth-to-thickness ratio to avoid lateral displacement when cycling thefunnel trap between open and closed (or vice-versa) it may instead bedesirable to double-up one flower member with another in a slip or pressfit or other telescoping fashion. So paired (or tripled), leaflet orpetal width can be maintained while their number is increased.

With this embodiment, the flower also has a shaft. This is typicallyreceived over an inner layer of the funnel trap braid. But it can alsobe positioned inside the inner layer and abut the distal fold of thefunnel trap extension. A proximal end of the shaft may be abutted by aheat shrink, glued or fused-on tube to maintain stability withoutincreasing proximal profile. With the flower overlaid by a/the outerbraid layer of the funnel trap structure, the entire assembly may besecured by an outer jacket of heat shrink of fused-on polymer layer.Suitable shrink and/or fusing materials include PTFE, FEP, PEBAX, PEEKor others. Adhesive bonding may alternatively be employed.

In the so-called J or hook-shaped embodiment, for proper recapture, itis important that the proximal end of the support members are able tofloat between the layers. This is so because of the way in which theangles of the braid change during compression. Accordingly, any suturesecuring the members in position relative to the braid that pass throughthe members should be located distally. Any proximal stabilizationfeatures should be looped around the members to allow translation orslipping.

The former embodiment (i.e., with the flower) may also use lateralstabilization features. However, in this embodiment, the proximal“shaft” of the flower is fixed or pinned with the braid and the braidshould slide or translate past the distal end of the leafs or petals. Assuch, any distal petal stabilization features should be of the loop-typedescribed above in this region.

Other approaches as further shown and described may be employed insupport member construction. Examples include laser-cut tubular bodies.Generally, these will be elastic (e.g., as produced in polymer) orsuperelastic (e.g., as cut from Nitinol hypotube). Such members may becut in a compressed or collapsed configuration and then plastically orthermally (i.e., as in heatsetting) formed to an expanded shape and thenso-assembled with the device embodiment braid. Various optionalconstructions and construction techniques are detailed below. So-too aredifferent braid layer assembly options.

The subject delivery and/or retrieval devices, kits in which they areincluded (with and without assembly), methods of use and manufacture(including assembly of the constituent components in vivo or ex vivo)are all included within the scope of the present disclosure. Someaspects of the same are described above, more detailed discussion ispresented in connection with the figures below.

Other systems, devices, methods, features and advantages of the subjectmatter described herein will be or will become apparent to one withskill in the art upon examination of the following figures and detaileddescription. It is intended that all such additional systems, devices,methods, features and advantages be included within this description, bewithin the scope of the subject matter described herein, and beprotected by the accompanying claims. In no way should the features ofthe example embodiments be construed as limiting the appended claims,absent express recitation of those features in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of the subject matter set forth herein, both as to itsstructure and operation, may be apparent by study of the accompanyingfigures, in which like reference numerals refer to like parts. Thecomponents in the figures are not necessarily to scale, emphasis insteadbeing placed upon illustrating the principles of the subject matter.Moreover, all illustrations are intended to convey concepts, whererelative sizes, shapes and other detailed attributes may be illustratedschematically rather than literally or precisely.

FIGS. 1A and 1B picture IVC filter variations as may be used in thepresent system.

FIG. 2 is a side view of a delivery and/or retrieval system with an endof any type of implantable medical device or foreign body.

FIG. 3 is a side-sectional view of a converted preform (i.e., a finallyshaped funnel section of the subject device) after heatsetting.

FIGS. 4A-4D are side sectional views illustrating an assembly approachwith the subject interposed support member(s).

FIGS. 5A-5D are side-sectional views illustrating interposed supportmember assembly options and features.

FIG. 6A is a perspective side view one support member in an as-cut orcompressed configuration; FIG. 6B is a side view of a/the support memberheatset in a splayed and flattened configuration. FIG. 7 is aperspective view of tooling for heatsetting a support member as shown inFIG. 6B.

FIG. 8A is a top view of an open support member; FIG. 8B is a top viewof paired support members.

FIG. 9 is an assembly view illustrating support member constructionaccording to heat-shrink material based approach.

FIG. 10 is another assembly view illustrating support memberconstruction with separate elements.

FIG. 11 is a side-sectional view a system including a shaft-basedsupport member.

FIG. 12A is a side view of another support member embodiment; FIG. 12Bis an assembly view of elements as shown in FIG. 12A.

FIG. 13 is an end view of an embodiment constructed with the assembly inFIG. 12B.

DETAILED DESCRIPTION

Various exemplary embodiments are described below. Reference is made tothese examples in a non-limiting sense, as it should be noted that theyare provided to illustrate more broadly applicable aspects of thedevices, systems and methods. Various changes may be made to theseembodiments and equivalents may be substituted without departing fromthe true spirit and scope of the various embodiments. In addition, manymodifications may be made to adapt a particular situation, material,composition of matter, process, process act(s) or step(s) to theobjective(s), spirit or scope of the present invention. All suchmodifications are intended to be within the scope of the claims madeherein.

Before the present subject matter is described in detail, it is to beunderstood that this disclosure is not limited to the particular exampleembodiments described, as such may, of course, vary. It is also to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting, since the scope of the present disclosure will be limited onlyby the appended claims.

All features, elements, components, functions, and steps described withrespect to any embodiment provided herein are intended to be freelycombinable and substitutable with those from any other embodiment. If acertain feature, element, component, function, or step is described withrespect to only one embodiment, then it should be understood that thatfeature, element, component, function, or step can be used with everyother embodiment described herein unless explicitly stated otherwise.This paragraph therefore serves as antecedent basis and written supportfor the introduction of claims, at any time, that combine features,elements, components, functions, and steps from different embodiments,or that substitute features, elements, components, functions, and stepsfrom one embodiment with those of another, even if the followingdescription does not explicitly state, in a particular instance, thatsuch combinations or substitutions are possible. Express recitation ofevery possible combination and substitution is overly burdensome,especially given that the permissibility of each and every suchcombination and substitution will be readily recognized by those ofordinary skill in the art upon reading this description

FIG. 1A shows a GÜNTHER TULIP (Cook Medical, Inc.) temporary IVC filter10 with a hook 12 end interface for retrieval. As shown in FIG. 1B foran IVC filter 20, the hook may be modified or substituted for anubbin-type interface 22. The nubbin (itself) may comprise alaser-formed or solder-formed protuberance or bump 24 on an extension 26from a hub 28. Alternatively, as shown in FIG. 2, a/the filter retrievalinterface 22 may comprise a band 24′ (e.g., a Pt marker band) mounted(e.g., by swaging, welding, gluing, etc.) on a/the extension 26. Howeverthe enlargement is created, the funnel-trap structures described beloware adapted to secure that feature for IVC filter retrieval.

FIG. 2 provides an overview of the subject system 100. A funnel-trapstructure 30 is shown made of heatset braid material 32. Theconstruction provides a flexible distal extension to an elongate shaft34. The shaft is received within an elongate sleeve 50 (that may be acommercially available catheter or a custom part of the overall system100) and may include a distal radiopaque marker band 52.

The braid may comprise Nitinol (preferably that is superelastic at bodytemperature), CoCr, Stainless Steel or another biocompatible material.It is advantageously braided material incorporating between 72 and 288,or between about 144 and 192 filament “ends” in a 1-over-1, 1-over-2,2-over-2 or other pattern. With (superelastic) Nitinol, the wire isadvantageously between about 0.001 and about 0.003 inches in diameter.In which case, a supple and relatively “smooth” matrix surface isprovided from which to construct the flexible funnel-trap architectureshown and described. The value of such a surface is in its atraumaticaspect and/or ability to help guide in IVC filter interface intoposition for capture even if it is oriented off-angle. Still, other wiresize and/or end count in a braid or other construction options arepossible as well.

To further assist with recapture, the funnel trap structure 30 may beselectably directable. As indicated by the arrows in FIG. 2, thematerial from which it is made can be heatset or otherwise configured toprovide a bias in an angular direction. The angle of deployment may beselectable or fully straightened by relative position of a core memberor obturator (not shown) or by a sleeve or catheter sheath as furtherdescribed. Further positioning may be achieved by rotating the device asfurther illustrated. Alternatively, a curved, “L” or “J” shaped wire maybe received within a lumen of shaft 34 that can be passed up to and/orthrough to the inside of the funnel trap structure. Made of superelasticNitinol (or other) wire, this member can be used to selectively shape ordirect the device end.

Other device articulation options for selecting the angular orientationof the funnel-trap portion of the device are possible as well. Any of avariety of steerable or directable catheter-type technologies (relianton pull-wires or otherwise) can be incorporated in shaft 34 for suchpurposes. Examples include the mechanisms described in U.S. Pat. Nos.4,723,936; 4,960,411; 6,251,092 and 8,273,073, each incorporated hereinby reference in its entirety, for such description.

The subject “funnel trap” may be generally frusto-conical in shape asshown or otherwise configured. With an outer conical shape (i.e., atriangular shape in cross section as shown) the structure is highlysupportive for any necessary or desirable tissue discretion that mightneed to occur to free an emplaced filter. Moreover, such a shapeprovides a flexible “waist” section 48 for the directable feature(s)noted above. Still, the device may be bowed outward along its sides orotherwise configured without departing from claimed inventive aspects orvariations.

Importantly, the distal rim opening 40 of the structure is larger thanthe more proximal rim opening 42 to operate in guiding filter engagementfeature(s) or enlargement 24/24′ into a pocket (P) where it is capturedand subsequently locked upon advancing sleeve 50.

Such a pocket is formed between braid walls 44 and bend 38, optionallyserving as an abutment feature with an edge or shoulder of nubbin/bump24/24′. To ensure capture, the sleeve 50 may be advanced fully over trap30 before withdrawal into a separate catheter. In other words, advancingsleeve 50 over funnel section 30 “closes the trap” and securely capturesthe implant to be retrieved. Otherwise, the sleeve may be a catheter.

Notably, system 100 may be used identically when capturing a filter 10with a typical hook end 12. However, the additional bulk/lateralextension of the hook may necessitate use of a relatively larger sleeveor catheter 50. In any case, system use may be visualizedfluoroscopically by a physician by way of marker features 24/24′ and 52and/or others as may be conveniently provided.

In the various system architectures, the catheter/pusher shaft and/orsleeve may comprise a simple extrusion (e.g., PTFE, FEP, PEEK, PI, etc.)or may be constructed using conventional catheter constructiontechniques and include a liner, braid support and outer jacket (notshown), metal hypotube, etc. Further, the filter frame may beconstructed using conventional laser cutting and electropolishingtechniques and/or be otherwise constructed. In embodiments intended fortracking through a guide/delivery catheter without an incorporatedsheath, a loading sheath may be employed. Advantageously, any suchloading sheath is splittable. Other typical percutaneous accessinstruments (such as wires, etc.), valves and other hardware may also beemployed in connection with the invention embodiments.

The funnel-trap structure 30 may be made as a subassembly and attachedto the catheter/pusher shaft. PCT publication PCT/US2014/042343(WO2014201380) and U.S. patent application Ser. No. 14/569,500, eachincorporated by reference in its entirety, detail optional steps in themanufacture of a pre-form for constructing the funnel-trap portion ofthe final device as shown if FIG. 3.

For IVC filter retrieval, the funnel-trap portion 30 shown may have adiameter (D) from about 5 mm to about 20 mm, or more preferably about 10to about 15 mm (i.e., size in a range to work within average size humanIVCs where such vessels are reported as having a mean diameter of 20 mmwithin a range of 13 to 30 mm). A length (L) may range from about 10 mmto about 30 mm. An overall cone angle (α) between braid walls 44 may bebetween about 30 and about 90 degrees. An angle (β) of bend 36 betweenbraid wall 44 and flap 46 may be between about 0 and about 60 degreesand flap length (F) may be between about 1 and about 10 mm in length.Overall, a funnel trap opening diameter (d) may be between about 5 andabout 95 percent of diameter (D) depending on the selected combinationof the noted variables (i.e., d, D, L, F, α and β). At the lower end ofthis range, the inner “opening” may be substantially closed such that itmust be pushed-open to receive the proximal engagement feature(s) of theimplant during retrieval. At the higher end of the range, the flap maylie completely along or in-line with the outer layer(s) of the device.The opening 40 of the funnel trap may be set at 90 degrees relative to adevice axis as shown. Otherwise, it may be angled or have a more complexshape as described in connection with FIGS. 9-13 in the above-referencedU.S. patent application Ser. No. 14/569,500, incorporated herein byreference.

Embodiments hereof include a support member or support members setwithin the funnel trap section or portion of the device. The supportmember(s) may be interposed between braid layers or set inside the braidlayers but interposed between heatset features. FIGS. 4A-4D illustratean approach to producing the former construction and a method ofmanufacture.

Here, braid 32 is manipulated (in FIG. 4A) flipping an outer layer (OL)over and then back (in FIG. 4B) upon an inner layer (IL) with supportmember 60 placement and abutment by a locating feature 110 in the formof shrink tubing. The braid layers are re-aligned and shrink tubing 110reduced in diameter by applying hot air in FIG. 4B. In FIG. 4C, funneltrap structure 30 is mounting on pusher member 34 using anotherjacketing shrink sleeve 112. In FIG. 4D, a final system assembly isshown with an outer sleeve 50 and optional proximal catheter jacket 114comprising PTFE shrink or other material.

FIGS. 5A provides an enlarged view of the funnel trap 30 plus supportstructure 60 shown in FIGS. 4A-4D. Here, the two-layer (IL and OL)construction of the trap 30 formed by heatsetting braid 32 is moreapparent. In this cross-section view, two “petals” 1, 3 of the supportstructure 60 “flower” are shown as well. In this example of a four-petalsupport member embodiment, petals (which would otherwise be numbered 2and 4) into an out of the plane of the figure are not show. A section ofa cylindrical base or shaft 62 of support structure 30 is, however,shown in cross-section.

FIG. 5B illustrates another support structure embodiment. Here separatesupport member 70, 72 “fingers” that are curled or hooked over into “J”shapes are independent of one another and stabilized between layers ofbraid. (As per the convention in FIG. 5B, the fingers into and out of ofthe page of the cross-section view are not shown.) Such member(s) may befurther stabilized by suture loop(s) passing through and/or around eachsuch member or body with knot(s) 74 securing the suture positionedwithin the interior of the outer walls 44 of the device.

The sutures may be looped around a single member and interwoven throughthe braid to form a guide or way. In another approach, the suture isformed in a ring around the circumference of the braid between itslayers (an option indicated by the dashed-line loops 76 in the figure)and tied to each member. Such a tie or knotting approach may befacilitated by forming various locator-type through holes in the member72, 74, etc. as by laser cutting, hypotube drilling or otherwise. Anexample of such an approach is shown in FIG. 11 (although in differentcontext).

In FIG. 5C, a support member 60 as described in FIG. 5A is placed withinthe funnel trap structure 30 inside its wall(s) 44. As such, petalnumber 2 is visible in the figures and extends like the others toadjacent fold 36 to support opening rim 40 (as indicated by dashedline).

In some ways, the support member placement in FIG. 5D resembles that inFIG. 5A; in other ways it is like that in FIG. 5C. The distinctionbetween the embodiments lies in that FIG. 5D shows a funnel trapconstruction 30′ incorporating two funnel trap preforms 30 a and 30 b.Thus, it may be said that the FIG. 5D construction takes the approach inFIG. 5C and adds a second, inner funnel trap to the construction.Alternatively, the FIG. 5D construction may be viewed as a doubling-upof layers relative to the FIG. 5A approach.

Regardless, the detail view in FIG. 5D includes five layers (A-D) ofmaterial. As shown, layer “C” identifies a/the support member 60 layer.However, other layers combinations are possible, as in an A-C-B—DEcombination (i.e., moving the support member 60 or members 72, 74, etc.outward one layer), A-B-D-C-E (i.e., moving the support layer inward onelayer) or A-B-D-E-C (i.e., moving the support layer inward two layers).However, the support is received, the doubled-up funnel 30′ approach(i.e., with subassemblies 30 a plus 30 b) may offer benefits when lowerbraid end counts or smaller diameter wires are desired in a given layerwhile maintaining overall braid density.

FIGS. 6A and 6B and FIGS. 8A and 8B detail methods of manufacture forcertain support member embodiments. FIG. 6A is a perspective side viewone support member in an as-cut or compressed configuration. In FIG. 6A,a tube (e.g., PET, PTFE or PEEK) is cut with four slits or slots todefine a support member 60 four petals 1, 2, 3, 4 leaving aninterconnected support base or sleeve 62. The cutting may be done with ablade or laser cutter. Use of a laser will facilitate the addition ofoptional stress-relief features 64 (dotted line) at the petal junctionsas well.

When cut in metal such as Nitinol, the relief features 64 may benecessary. In plastic, they are not. In either case, the body shown inFIG. 6A is advantageously heatset in a splayed-out form as shown in FIG.6B. This can be accomplished in connection with tooling 80 asillustrated in FIG. 7 and a heatsetting or annealing oven. The toolingmay comprise a shaft or rod 82 to center the support member shaft orsleeve 62 and washers 84 a, 84 b for compressing petals 1-4 flat.

FIG. 8A provides a top view of a support member 60 so-set. With thematerial heatset open and flat (or set in an approximately conicalshape), the structure assists the resiliency of the braid 32 in openingthe funnel trap structure 30 upon deployment. FIG. 8B illustrates how afirst support member 60 a can be nested with a second support member 60b to form a combined support member 60′.

In this case, the nesting doubles the number of support petals. Theapproach (i.e, nesting of at least two support member sub-assemblies)offers a maximum number of petals, with maximum possible pedal widtheach (as compared to cutting more petals out of a single tube). Themaximized width may be particularly useful in providing lateralstability for the elements when constructed of thin material (e.g., onthe order of 0.002 to about 0.005 inches thick) and/or avoiding pushingor poking through the braid the members are intended to support.

FIG. 9 illustrates still another approach to support memberconstruction. Here, a support 120 is constructed using tubing (e.g., PETor PEEK heat shrink) that is heat shrinked or formed onto a mandrel 130.A cylindrical portion 132 of the mandrel provides a round interfaceportion 122 of the support for mounting to the device shaft 34. Flats134 on the mandrel result in flat portions or petals 124 in the support.When originally formed by heat shrinking on the mandrel, the petals areconnected. However, they are cut with shears, a razor blade or otherwisealong squared edges (dashed lines) formed by edges 136 of the mandrel.

One such support may be used in a construct as described above.Otherwise a pair (or more) may be nested concentrically. When stacked ornested, as before, the petals are advantageously offset from oneanother. A symmetrical offset of 45 degrees is advantageous for supportmembers each including four petals, thus providing a combined structurewith eight symmetrically arranged support petals. With a support memberformed with three petals to be nested with another to form a finalconstruct with six petals, the offset between each petal isadvantageously 60 degrees.

Also, it is possible to plastically deform and set the petals splayedoutwards. In a heat-shrink embodiment, it should be done mechanically(i.e., without significant heating), in order to avoid inadvertent(mis)shaping by unintended recovery of the heat shrink tubing.Nevertheless, when two support bodies are employed in a concentricarrangement, they may heat-staked together using a soldering iron tip bycross-wise penetration (or otherwise joined, e.g., by adhesive wickedbetween the bodies) in order to maintained the desired spacing of petalsor for any other reason. The same approach (i.e., heat staking, etc.)may be employed in connection with the FIG. 8B embodiment as well.

FIG. 10 illustrates yet another approach to support member construction.Here, a support 140 is constructed either on the end of a shaft 34 (asshown) or as a separate subassembly to be used like other examplesabove. Either way, the support comprises a plurality of independentextension members 142. These may be formed by die cutting or lasercutting PET, PEEK or another sheet material. And then located as shownonto a support body via guide or eye holes 144. The eye holes may bealigned along axes 146 with wires (wire axes shown) that are removedafter affixing the complimentary features (e.g., by gluing, laserwelding or fusing by typical catheter constructions techniques orotherwise).

The construct in FIG. 10 may be employed in the support member nestingapproach shown in FIG. 11. Alternatively, a tubular shaft 34 can beprocessed such that its distal end is cut into a support member section90 with finger or petal extensions 91, 92, 93, etc. therefrom. Theseextensions can be heatset as described in connection with FIG. 7 or intoa conical shape using a matching tool or form. For shape or heatsettingpurposes, the shaft advantageously comprises PET or PEEK (as such aselection provides a good compromise in strength, machinability andformability) or Nitinol. The cutting may be performed with a laser andinclude stress relief features 96 at a junction of the shaft body 34 andextensions. Optional zig-zag end features 98 may also be included in theconstruction. These zig-zag, square-wave or other such engaging featurescan assist in maintaining stable position of the support member fingerswhen the braid of rim opening 40 is compressed and contacting the same.Notably, the same such features may be included in the FIG. 10 and/orFIGS. 12A and 12B embodiment as shown or others as provided herein.

In FIG. 11, the funnel trap embodiment 30 also includes an optionalsecond support member 60 interposed between its braid layers (IL andOL). Notably, the support member 60 fingers 1, 2, etc. areadvantageously staggered or interdigitated (as in the manner shown inFIG. 8B) with extensions 5 and 6, etc. coordinated to maximize thenumber of non-overlapping elements and provide uniform spacing of radialsupport points for opening rim 40.

In such a system 100, the extension section 30 may be located as shownand bonded with one or more PEBAX (or other thermoplastic material)layers 102 to shaft 34. A laser welding approach is alsopossible—particularly for embodiments in which all elements are madeNitinol although other materials might be employed to the same effect.

FIG. 12A illustrates a laser cut pattern that may be used for theextension sections of a shaft-cum-support as discussed above.Alternatively, the pattern may define the geometry of a separate support150 as shown.

In either case, the shape includes a plurality of extensions 151, 152,153 and 154 in the form of substantially triangular petals, fingers orleaflets. So-configured, the available distal interface area 156 of eachmember to support the funnel trap braid 32 is maximized in size, whileminimizing a waist or flexure section 158 for each petal. The minimizedwaist provides space for (optionally) radiused stress relief features160 from a base or stem section 160.

Support member 150 may be so-cut from Nitinol tubing or other material.The cut pattern may include an open stress-relief area 164 comprising aplurality of curved or otherwise configured beams 166 within stemsection 160. Such a section will serve as one or more windows forflow-through of bonding material (e.g., thermoplastic PEBAX—or othermaterial—as noted above) without significant increase in stiffnessacross the entire base 160 of the structure. Alternatively, square orrectangular shaped windows may be provided for bonding. In either case(i.e., with complex, curved windows or rectilinear forms), the windowsin each base are advantageously set or “clocked” such that theextensions 151, etc. are spaced apart as desired when the windows arealigned for bonding material flow-through. A proximal rim or band 168 ofeach support member 150, 150′ will prevent pull-out from flow-throughbonding approach.

A wide proximal or distal rim or band 170 (i.e., as shown) can—ineffect—serve as an integrated radiopaque marker to a/the built-upsystem. As another option, an inner extent or “frame” portion of one ormore aligned windows can be laser welded together to stabilize overallsupport member 150, 150′ position for further assembly processing. Yetanother option is to laser or resistance weld proximal or distal rim orband 168, 170 for such purpose(s).

Still further, each rim (or an integrated rim without an intermediatestress-relief section or area 164) may be split as shown, even if cutfrom cylindrical tubing. A split line 172 may be used for nesting onesuch tube with another. If the kerf or separation of the split line iswide enough, the base 160 may be compressed and fit inside another tubeoriginally of the same size. Alternatively, a split pair may be employedwhere one contracts and the other expands.

FIG. 12B illustrates assembly of a pair of support members 150 and 150′.In this example, neither base is split. Rather, the tubes from which thepatterns are cut are sized to nest with each other. The base 160 of eachbody may include a relief pattern 164 configured to match-up when theyare set concentrically with each other and offset (e.g., as suggested bythe curved arrow so the so-called fingers or petals do not overlap.Alternatively (as shown), the relief patterns may be configured so thatthey are non-aligned with the petals offset. Such an approach mayprovide more uniform flexibility.

For use, petal extensions 151, 152, etc. are typically heatset outwardly(as shown) and end interface sections 156 may retain the curvaturenative to the tube from which they are cut. In which case, any includedzig-zag end pattern along with interior relief 174 may provideflexibility when opening or deploying the funnel trap device. Otherwise,the interface sections may be heatset flat (or at least partially flat)for one or both of the support members 150, 150′. In which case, theaforementioned flexibility will assist in fully compressing the devicefor tracking and/or retrieval. Without such a pattern provided,associated part width or thickness may be altered if so-desired.

With a relief section 174, distal interface 156 (whether zig-zagged,flat or otherwise configured) portions are shown supported by struts176. Alternatively, relief space 174 may be omitted. Such an embodiment(not shown) may employ a single central strut as part of an overall “T”shaped body.

In any case, FIG. 13 is an end view of a device 100 funnel section 30with support members 150/150′ set within braid material 32. It can beobserved through the braid that alternating petals X, Y are wider andnarrower, respectively. This is a result of cutting maximum widthinterface sections 156 from larger and smaller tubing, respectively, fornesting.

With the split-tube approach, the same size interface sections 156 maybe provided. However, upon compression, narrower “Y-type” members maycompress better (i.e., to their native tube size) offering a reduceddevice crossing profile. Stated otherwise, excessive dimensionalstack-up can be avoided if a mix of X- and Y-type or sized members areprovided. Such a consideration may be of use in minimizing lockingsleeve 50 size, if used.

Variations

The subject methods, including methods of use and/or manufacture, may becarried out in any order of the events which is logically possible, aswell as any recited order of events. Medical methods may include any ofa hospital staff's activities associated with device provision, implantpositioning, re-positioning, retrieval and/or release.

Furthermore, where a range of values is provided, it is understood thatevery intervening value, between the upper and lower limit of that rangeand any other stated or intervening value in the stated range isencompassed within the invention. Also, it is contemplated that anyoptional feature of the inventive variations described may be set forthand claimed independently, or in combination with any one or more of thefeatures described herein.

Though the invention has been described in reference to severalexamples, optionally incorporating various features, the invention isnot to be limited to that which is described or indicated ascontemplated with respect to each variation of the invention. Variouschanges may be made to the invention described and equivalents (whetherrecited herein or not included for the sake of some brevity) may besubstituted without departing from the true spirit and scope of theinvention.

Reference to a singular item includes the possibility that there are aplurality of the same items present. More specifically, as used hereinand in the appended claims, the singular forms “a,” “an,” “said,” and“the” include plural referents unless specifically stated otherwise. Inother words, use of the articles allow for “at least one” of the subjectitem in the description above as well as the claims below. It is furthernoted that the claims may be drafted to exclude any optional element. Assuch, this statement is intended to serve as antecedent basis for use ofsuch exclusive terminology as “solely,” “only” and the like inconnection with the recitation of claim elements, or use of a “negative”limitation.

Without the use of such exclusive terminology, the term “comprising” inthe claims shall allow for the inclusion of any additionalelement—irrespective of whether a given number of elements areenumerated in the claim, or the addition of a feature could be regardedas transforming the nature of an element set forth in the claims. Exceptas specifically defined herein, all technical and scientific terms usedherein are to be given as broad a commonly understood meaning aspossible while maintaining claim validity. Accordingly, the breadth ofthe different inventive embodiments or aspects described herein is notto be limited to the examples provided and/or the subject specification,but rather only by the scope of the issued claim language.

1-20. (canceled)
 21. An apparatus for delivery or retrieval of avascular medical device, the apparatus comprising: an elongate shafthaving an axis and a flexible distal extension comprising a braidstructure folded back at a first fold to form two layers, the two layersfolded back inwardly at a second fold such that the first fold is aproximal opening of a funnel and the second fold is a distal opening ofthe funnel, wherein the proximal opening of the funnel is configured toreceive a proximal end of a vascular medical device; and a supportmember coupled to the elongate shaft, the support member comprising aplurality of elongate support elements that extend between the twolayers to the second fold of the braid structure.
 22. The apparatus ofclaim 21, further comprising an elongate sleeve receiving the elongateshaft and flexible distal extension.
 23. The apparatus of claim 21,further comprising the vascular medical device.
 24. The apparatus ofclaim 23, wherein the vascular medical device is an inferior vena cavafilter.
 25. The apparatus of claim 21, wherein the plurality of elongatesupport elements comprise zig-zag distal interfaces.
 26. The apparatusof claim 21, wherein the support member comprises two concentric bodies.27. The apparatus of claim 21, wherein the support member comprises twobodies that are offset from one another in angular relation.
 28. Theapparatus of claim 21, wherein a distal end of at least one of theplurality of elongate support elements is wider than a proximal end ofthe at least one of the plurality of elongate support elements.
 29. Theapparatus of claim 21, wherein at least one of the plurality of elongatesupport elements has a surface relief, wherein the surface reliefextends between a distal end and a proximal end of the at least one ofthe plurality of elongate support elements and along a longitudinal axisof the at least one of the plurality of elongate support elements. 30.The apparatus of claim 21, wherein at least one of the plurality ofelongate support elements comprises a triangular petal.